JPH0560313A - Method of introducing combustion air and combustion apparatus - Google Patents

Abstract

PURPOSE: To reduce the amount of waste gas by directly unloading an exhaust gas at one region of high-temperature primary air that has not been used up at the upper portion of an object to be burnt for introducing it to primary combustion air again and reducing the combustion air. CONSTITUTION: A combustion space 14 is provided at the upper portion of a combustion fire lattice 5 and the front of the space 14 is terminated by a waste gas path 15. When an object to be burnt is burnt at the front of the fire lattice 5, the large part of primary air from a ventilation machine 12 is introduced via chambers 7-9. A waste gas in the combustion space 14 is unloaded via an exhaust path 24 that is connected to the suction side of a ventilation machine 25 from an exhaust opening 23 and is connected to the suction side of the primary air ventilation machine 12 via a compression side passage 26. Then, an exhaust waste gas is pressed to a passage 13 and is introduced to the chambers 7-11 as secondary air along with the primary air. Also, nozzles 21 and 22 are provided at the lower region of the waste gas path 15, secondary combustion air is introduced to the waste gas for burning a flammable constituent in the waste gas again, thus reducing the amount of waste gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention introduces primary combustion air through combustion products and secondary combustion air directly into a waste gas stream.
Further, the present invention relates to a method for introducing combustion air in grate combustion in which a part of the waste gas is branched from the waste gas stream and reintroduced into the combustion process. The invention also relates to a combustion device for carrying out the above method.

[0002]

2. Description of the Related Art In a mechanical combustion grate apparatus, required combustion air consisting of primary combustion air and secondary combustion air is usually additionally supplied. The primary combustion air is the grate structure itself,
That is, the secondary combustion air is supplied to the combustion products on the combustion grate through the grate aggregate and is sent to the delayed combustion region of the combustion space above the combustion grate. In order to completely burn off not only solid but also gaseous combustion residues, combustion air is introduced in a stoichiometric amount or more in any combustion grate device.
That is, more combustion air is introduced than is required in the ideal case for complete oxidation of the combustion products. However, in the operation method in which the stoichiometric amount is exceeded, so to speak, it is necessary to heat the excess combustion air, which is a surplus, so it is unavoidable that the efficiency of the waste heat boiler connected after the combustion grate device decreases. In conventional combustion grate devices, the stoichiometric ratio is in the range 1.4 to 2.2.

A large number of combustion grate devices are arranged in a large number of primary air regions in the flow direction of the combustion products. This arrangement in the different regions makes it possible to introduce the necessary and sufficient primary combustion air depending on the combustion rate of the combustion product at that time. Since burned-out combustion products usually accumulate in the aft region of the combustion grate, primary combustion air is often introduced into the aft region only for the purpose of cooling the slag and maintaining the mechanical function of the grate floor. It No conversion by chemical reactions occurs anymore in this region. Therefore, the gas in the area above the combustion grate in the combustion space region is not very warm and its composition is very close to that of the introduced primary combustion air.

The part of the primary combustion air that is no longer involved in chemical reactions significantly increases the overall gas volume. As a result, devices connected after the combustion space, such as waste heat boilers, waste gas purification devices, are correspondingly large and expensive. Also, as mentioned above, excess air reduces the efficiency of this type of combustion device. In addition, the excess amount of air generates a large amount of harmful substances such as carbon monoxide and nitric oxide.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method which can reduce the amount of waste gas flow and eliminate the above-mentioned drawbacks caused by excess air, and an apparatus for implementing the method.

It is already known to exhaust the exhaust gas from the device and reintroduce it into the combustion process to reduce the oxygen content in the exhaust gas, but conventionally the exhaust gas is after the process of the cooling section, ie,
After passing through the waste heat boiler or the waste gas purifier, it is finally exhausted. However, this configuration does not reduce the gas volume of the waste gas and still has to absorb this large waste gas volume.

[0007]

Therefore, according to the method of the present invention, the present invention exhausts the waste gas directly above the combustion product in a region of a portion of the hot primary air that has not been used up, It is reintroduced into the combustion air and the amount of combustion air is reduced according to the amount of waste gas added.

According to this method, the amount of waste gas is reduced as a whole by the amount that is exhausted in the rear combustion space and reintroduced into the combustion air. Further, as described above, this waste gas does not cause a chemical reaction and its composition is almost comparable to that of fresh combustion air, so that the amount of fresh combustion air can be reduced accordingly. In the case of the known method, the exhaust gas is exhausted above the combustion grate where the exhaust gas mixes with each other as a whole, and since the exhaust gas no longer contains the oxygen component necessary for combustion, fresh combustion air is equivalent to the above. Can not be reduced significantly.

When the total volume of waste gas is reduced, the device following the combustion space can be downsized, and therefore the device cost can be significantly reduced. Further, as an advantage of the operating method of the present invention, there is a reduction in the amount of harmful substances such as carbon monoxide and nitric oxide generated. The effect of reducing carbon monoxide is achieved by vigorous additional combustion of a gas stream containing a relatively large amount of toxic substances. Further, the effect of reducing nitric oxide is due to a decrease in concentration due to a decrease in oxygen content in the waste gas.

It is preferable to exhaust the waste gas in a volume corresponding to the amount of primary air introduced into the rear primary air region, at which time the maximum effect is obtained.

However, it is also possible to make the amount of exhaust waste gas smaller than the amount of primary air introduced into the combustion grate in the rear primary air region, or conversely, to correspond to a larger volume.

The amount of exhausted exhaust gas is mixed with the primary combustion air or the secondary combustion air. When combusting domestic refuse, it is preferable to use exhaust gas as secondary combustion air exclusively. This is because the amount of combustion air that is introduced and exhausted in the region of the rear grate generally corresponds approximately to the amount required for secondary combustion air.

Claims 8 to 13 describe preferred constructions of the apparatus for carrying out the method of the invention.

The present invention will be described in detail below with reference to examples.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, a combustion apparatus is equipped with a funnel-shaped feeder 1 for feeding combustion products onto a feeding table 3.
The supply runway 2 is connected to this. Loading bar 4 on the supply table 3
Are provided so as to be movable back and forth, and the combustion products from the supply slideway 2 are fed onto the combustion grate 5. Combustion products are burned on this grate. The slant type and the horizontal type of the grate 5 can be handled in principle in the same manner.

Below the combustion grate 5, an introduction device for the primary combustion air is provided and is generally designated by 6. This device has a number of chambers 7 to 11 in which primary combustion air is introduced into the chambers by means of a fan 12 via passages 13. By providing the chambers 7 to 11, the combustion grate 5 is subdivided into a large number of forced draft regions, so that the primary combustion air can be adjusted in various ways as needed on the grate 5.

A combustion space 14 is provided above the combustion grate 5. The front part of this space terminates in the waste gas passage 15. An additional device such as a waste heat boiler or a waste gas refining device (not shown) is connected to the waste gas passage. Later in Figure 3
In the lower area, the ceiling 16 and the rear wall 1 as described by
7, the side wall 18 forms the combustion space 14.

Combustion of the combustion products 19 occurs in the front part of the combustion grate 5 having the waste gas passage 15 provided above. Most of the primary combustion air is introduced in this area via the chambers 7, 8, 9. Burned-out combusted material, that is, slag, is generated in the rear portion of the combustion grate 5, and the primary combustion air introduced into this region through the chambers 10 and 11 substantially cools the slag, and particularly the combustion grate 5 is discharged. Only by cooling, this keeps the grate 5 functioning well.

Then, the slag falls to the slug extracting portion 20 at the end of the combustion grate 5. Nozzles 21 and 22 are provided in the lower region of the waste gas passage 15, and secondary combustion air is introduced into the waste gas from here to vigorously reburn combustible components in the waste gas.

In the illustrated embodiment, the ceiling 16, the rear wall 17, the side wall
The rear part of the combustion space 14 is formed by 18, and the waste gas is exhausted substantially in this rear part. For this reason,
In this embodiment, the exhaust opening 23 is provided in the ceiling 16, and the waste gas is exhausted by the ventilator 25 through the exhaust passage 24 connected to the intake side of the ventilator. A passage 26 on the compression side of the fan
Is connected, and the amount of exhaust gas is pushed into the passage 13 through the passage and introduced into the chambers 7 to 11 by the primary combustion air.

In the embodiment of FIG. 2, an exhaust opening 23 is provided in the rear wall 17. The passage 26 connected to the compression side of the fan 25 in this embodiment is connected to, for example, the nozzle 21 for introducing a part of the secondary combustion air.

In the embodiment shown in FIG. 3, the side wall of the combustion space 14
Two exhaust openings 23 are formed in 18, and an exhaust passage 24 connected to these is connected to the intake side of the fan 12. The exhaust passage is provided with a connecting pipe 27 having a shutoff valve 28, through which fresh air is replenished and mixed with the waste gas.

[0023]

As described above, according to the present invention, it is possible to increase the efficiency of the combustion device by exhausting the waste gas flow from the specific region of the device and effectively utilizing it. Further, since the amount of waste gas can be reduced, the scale of the entire device including the subsequent waste heat boiler and waste gas purification device can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a structure of a first embodiment of a combustion apparatus.

FIG. 2 is a longitudinal sectional view showing the structure of a second embodiment of the combustion device.

FIG. 3 is a sectional view showing still another embodiment of the combustion device.

[Explanation of symbols]

 5 Combustion grate 6 Primary combustion air introduction device 14 Combustion space 21 Nozzle 23 Waste gas exhaust path 24 Waste gas exhaust path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Johannes Joseph Edmund Martin Federal Republic of Germany, 8124 Seishiupt, Saint. No. 55, Heinlitshashi Utrase

Claims (13)

[Claims] 1. The primary combustion air is introduced into a waste gas stream directly through a combustion product, and a part of the waste gas is branched from the waste gas stream and reintroduced into the combustion process. In the method of introducing combustion air in grate combustion, exhaust gas is directly exhausted in the upper part of the burned material, a part of the unused high temperature primary air, and re-introduced into the combustion air, and burned according to the amount of added waste gas. A method for introducing combustion air, characterized by reducing air. 2. The method for introducing combustion air according to claim 1, wherein the amount of exhaust waste gas corresponds to a volume corresponding to the amount of primary combustion air introduced into the combustion grate in the rearward primary air region. .. 3. The method for introducing combustion air according to claim 1, wherein the amount of exhaust waste gas corresponds to a volume smaller than the amount of primary combustion air introduced into the combustion grate in the rear primary air region. .. 4. The method of introducing combustion air according to claim 1, wherein the amount of exhaust waste gas corresponds to a volume larger than the amount of primary combustion air introduced into the combustion grate in the rear primary air region. .. 5. The method for introducing combustion air according to claim 1, wherein an amount of exhaust waste gas is mixed into the primary combustion air. 6. The method for introducing combustion air according to claim 1, wherein the amount of exhaust waste gas is mixed into the secondary combustion air. 7. The method for introducing combustion air according to any one of claims 1 to 4, wherein the amount of exhaust gas waste is used exclusively as secondary combustion air when combusting domestic waste. 8. A combustion grate, a device provided below the combustion grate for introducing primary combustion air through the combustion grate, and a device communicating with the combustion space above the combustion grate. A combustion device for carrying out the method according to any one of claims 1 to 7, comprising a nozzle for introducing secondary combustion air, in a combustion space (14) above a combustion grate (5). A combustion device, wherein at least one exhaust gas exhaust passage (23, 24) is provided. 9. Combustion device according to claim 8, characterized in that the exhaust opening (23) of the exhaust passage (24) is provided in the ceiling region (16) of the combustion space (14). 10. Combustion according to claim 8, characterized in that the exhaust opening (23) of the exhaust passage (24) is provided in at least one side wall (18) of the combustion space (14) above the combustion grate (5). apparatus. 11. The exhaust opening (23) of the exhaust passage (24) is provided in the rear wall (17) of the combustion space (14) above the combustion lattice (5), according to any one of claims 8 to 10. Burning device. 12. An exhaust passage (24) is connected to an intake side of a fan (25), and a compression side of the fan is connected to a primary combustion air introducing device (6) via a passage (26). The combustion device according to any one of claims 8 to 11, characterized in that: 13. An exhaust passage (24) is connected to an intake side of a fan (25), and a compression side of the fan communicates with an upper part of a combustion grate (5) in a combustion space (14). 12. The combustion device according to claim 8, wherein the combustion device is connected to a nozzle (21) for introducing secondary combustion air via a passage (26).